This is a proposal to renew the ongoing, productive drug abuse Treatment Research Center located in the John Hopkins Behavioral Pharmacology Research Unit. The Center unites a group of innovative and productive drug abuse clinical researchers with complementary interests and approaches who share a commitment to the scientific study of drug abuse as a behavioral pharmacologic disorder. The Center integrates human laboratory research with outpatient clinical trials research. Its clinical research resources training and career development resources, and scientific reputation and productivity are outstanding. The general theme for this renewal period is that of treatment comparisons. Five specific components plus a Core are proposed. A human laboratory component will use a naloxone-precipitated withdrawal model to evaluate medications that may suppress the opioid withdrawal syndrome. A second human laboratory component will evaluate factors that influence the persistence of heroin-self administration during methadone maintenance treatment. A clinical trial component will assess the individual and combined effects of opioid pharmacotherapy dose and varied incentive-based behavior therapy "doses" in treating combined opioid and cocaine abuse; this study will help to identify which intensities of psychosocial treatment most sensitively reveal the efficacy of pharmacotherapies. A second clinical trial component will assess whether a specific behavior therapy previously shown to be an effective adjunct to methadone--behaviorally-contingent pharmacotherapy--is also effective as an adjunct to LAAM. The fifth component involves both human laboratory studies and clinical trials: human laboratory studies will compare the withdrawal syndromes following discontinuation of methadone, LAAM and buprenorphine; a clinical trial will compare the efficacies and patient acceptabilities of methadone, LAAM and buprenorphine in detoxification treatment. A Core component provides shared resources for patient recruitment, urinalysis testing, statistical analyses, technical/computer support, psychiatric/behavioral assessment, medical supervision, pharmacy preparations, and office and administrative support.